Thermal detectors are often used in thermal (infrared) imaging systems such as night vision equipment. A thermal detector may include an array of thermal sensors that detect thermal radiance differences between various objects in a scene and that display these differences as a thermal image of the scene. The thermal sensors may define respective picture elements or pixels of the resulting thermal image.
One type of thermal sensor includes a thermal element disposed between a pair of electrodes. The electrodes may constitute capacitive plates to the thermal element, which may constitutes a dielectric disposed between the capacitive plates. The thermal sensor may be electrically and mechanically coupled to a substrate.
To maximize thermal response and enhance thermal image accuracy, thermal sensors are preferably isolated thermally from one another and from the associated substrate. Such thermal isolation ensures that the signals from each thermal sensor accurately represents incident infrared radiation. Several approaches have been used to enhance thermal isolation between the thermal sensors and the underlying substrate. These approaches have generally sacrificed other qualities of the thermal sensors to obtain enhanced thermal isolation.